Three-dimensional printing

Abstract

An example of a penetrating agent for a three-dimensional (3D) printing process includes a surfactant blend, a co-solvent, a humectant present in an amount ranging from about 2 wt % to about 10 wt %, based on a total weight of the penetrating agent, and a balance of water. The surfactant blend includes a first non-ionic surfactant having a first hydrophilic chain length, a second non-ionic surfactant, wherein the second non-ionic surfactant is selected from the group consisting of a polyether siloxane and an alkoxylated alcohol, and an anionic surfactant.

What is claimed is: 
     
         1 . A penetrating agent for a three-dimensional (3D) printing process, comprising:
 a surfactant blend including:
 a first non-ionic surfactant having a first hydrophilic chain length; 
 a second non-ionic surfactant, wherein the second non-ionic surfactant is selected from the group consisting of a polyether siloxane and an alkoxylated alcohol; and 
 an anionic surfactant; 
   a co-solvent;   a humectant present in an amount ranging from about 2 wt % to about 10 wt %, based on a total weight of the penetrating agent; and   a balance of water.   
     
     
         2 . The penetrating agent as defined in  claim 1  wherein the penetrating agent has a surface tension ranging from about 19 dynes/cm to about 29 dynes/cm. 
     
     
         3 . The penetrating agent as defined in  claim 1  wherein the surfactant blend further includes a third non-ionic surfactant having a second hydrophilic chain length that is different than the first hydrophilic chain length. 
     
     
         4 . The penetrating agent as defined in  claim 1  wherein:
 the first non-ionic surfactant is present in an amount ranging from about 0.1 wt % to about 1.5 wt %, based on the total weight of the penetrating agent; 
 the second non-ionic surfactant is present in an amount ranging from about 0.1 wt % to about 1.5 wt %, based on the total weight of the penetrating agent; and 
 the anionic surfactant is present in an amount ranging from about 0.1 wt % to about 1.5 wt %, based on the total weight of the penetrating agent. 
 
     
     
         5 . The penetrating agent as defined in  claim 1  wherein the co-solvent is present in an amount ranging from about 5 wt % to about 25 wt %, based on the total weight of the penetrating agent. 
     
     
         6 . A three-dimensional (3D) printing kit, comprising:
 a build material composition including a polymer;   a liquid functional agent to be applied to at least a portion of the build material composition during 3D printing, the liquid functional agent including an active material; and   a penetrating agent to be applied with the liquid functional agent to the at least the portion of the build material composition during 3D printing, the penetrating agent including:
 a surfactant blend including:
 a first non-ionic surfactant having a first hydrophilic chain length; 
 a second non-ionic surfactant, wherein the second non-ionic surfactant is selected from the group consisting of a polyether siloxane and an alkoxylated alcohol; and 
 an anionic surfactant; and 
 
 a liquid vehicle including a humectant present in an amount ranging from about 2 wt % to about 10 wt %, based on a total weight of the penetrating agent. 
   
     
     
         7 . The 3D printing kit as defined in  claim 6  wherein:
 the build material composition has a surface energy density ranging from about 0.02 J/m 2  to about 0.046 J/m 2 ; and 
 the penetrating agent has a surface tension ranging from about 19 dynes/cm to about 29 dynes/cm. 
 
     
     
         8 . The 3D printing kit as defined in  claim 6  wherein the liquid functional agent is a fusing agent and the active material is an energy absorber to absorb electromagnetic radiation to coalesce the polymer in the at least the portion. 
     
     
         9 . The 3D printing kit as defined in  claim 8  wherein one of:
 the fusing agent is a core fusing agent and the energy absorber has absorption at least at wavelengths ranging from 400 nm to 780 nm; or 
 the fusing agent is a primer fusing agent and the energy absorber has absorption at wavelengths ranging from 800 nm to 4000 nm and has transparency at wavelengths ranging from 400 nm to 780 nm. 
 
     
     
         10 . The 3D printing kit as defined in  claim 6  wherein the liquid functional agent is a coloring agent selected from the group consisting of a black agent, a cyan agent, a magenta agent, and a yellow agent, and the active material is a colorant. 
     
     
         11 . A method for three-dimensional (3D) printing, comprising:
 applying a build material composition to form a build material layer, the build material composition having a surface energy density ranging from about 0.02 J/m 2  to about 0.046 J/m 2  and including a polymer;   based on a 3D object model, selectively applying a plurality of agents on at least a portion of the build material layer, the plurality of agents including a liquid functional agent and a penetrating agent, the penetrating agent having a surface tension ranging from about 19 dynes/cm to about 29 dynes/cm and including:
 a surfactant blend including:
 a first non-ionic surfactant having a first hydrophilic chain length; 
 a second non-ionic surfactant, wherein the second non-ionic surfactant is selected from the group consisting of a polyether siloxane and an alkoxylated alcohol; and 
 an anionic surfactant; 
 
 a co-solvent; 
 a humectant present in an amount ranging from about 2 wt % to about 10 wt %, based on a total weight of the penetrating agent; and 
 a balance of water; and 
   based on the 3D object model, forming a 3D object layer from the at least the portion of the build material layer.   
     
     
         12 . The method as defined in  claim 11  wherein the selectively applying of the plurality of agents is accomplished in a single printing pass. 
     
     
         13 . The method as defined in  claim 11  wherein the selectively applying of the plurality of agents is accomplished at a fluid density ranging from about 36 ng/600 th  of an inch 2  of the build material composition to about 90 ng/600 th  of an inch 2  of the build material composition. 
     
     
         14 . The method as defined in  claim 11  wherein:
 the liquid functional agent is a coloring agent; 
 the 3D object layer formed is a colored layer having a colorant of the coloring agent embedded therein; and 
 the method further comprises:
 applying a sacrificial build material layer on the colored layer; and 
 based on the 3D object model, selectively applying the penetrating agent and the coloring agent on at least a portion of the sacrificial build material layer. 
 
 
     
     
         15 . The method as defined in  claim 11  wherein:
 the liquid functional agent is a fusing agent; and 
 the forming of the 3D object layer involves exposing the build material layer to electromagnetic radiation to coalesce the build material composition in the at least the portion.